Arizona congresswoman recovering after shooting

Jared Lee Loughner, 22, went on a shooting rampage, while the Democratic politician was attending a political meeting in a supermarket parking lot in Arizona.

Giffords is said to be in a critical condition but is able to follow simple commands, such as holding up two fingers when asked, according to doctors at University Medical Center in Tucson.

A single bullet travelled the length of her brain on the left side, hitting an area that controls speech. Given the devastating wound, doctors said they were uncertain about the extent of brain damage she may have suffered.

US federal judge John Roll and a 9-year-old girl were among the six people killed, while fourteen others were wounded.

Loughner has been charged with two counts of first degree murder, one count of attempted assassination of a member of Congress and two other counts of attempted murder. Prosecutors say other charges could be filed.

He is due to appear in court in Phoenix at 1400 (2100 GMT) on Monday as reports emerge of a troubled man who had been asked to leave a local college for disruptive behaviour.

Investigators said in the charges they found an envelope at his residence with the handwritten phrases "I planned ahead" and "My assassination," along with the name "Giffords" and what appeared to be Loughner's signature.

The father of the slain 9-year-old girl said she was born on September 11, 2001 - the day of the hijacked plane attacks on New York and Washington. "She came into the world on 9/11 and then at 9 years old she leaves it all on this terrible day," John Green said.

Gun violence is common in the United States but political shootings are rare.

Investigators were looking at a rambling Internet manifesto left by Loughner or someone writing under that name. There was no coherent theme to the writing, which accused the government of mind control and demanded a new currency.

Loughner withdrew from Pima Community College in October 2010 after several encounters with campus police, college officials said in a statement. He was told to obtain a mental health clearance if he wished to return to school to show his attendance would not present a danger to himself or others.